With DM particles in this mass range it is not immediately possible to explain the EDGES anomaly. Nevertheless, it was pointed out recently [1]} that the effect of a millicharged subcomponent on the baryon temperature is enhanced if there is an additional force between the millicharged sub-component and the dominant neutral DM component. Such a force is automatically present in our set-up, because both components couple to dark photons. However, in contrast to what was assumed in Ref. [1]} the force mediated by dark photons does not become stronger at small velocities, because the dark hydrogen only has dipole interactions. It will be very interesting to investigate whether such a short-range force can also help to alleviate the tension between the EDGES anomaly and other cosmological observations.
